添加菜单快捷键（swing）

(1) SketchFrame.java

package com.service;   import javax.swing.ButtonGroup; import javax.swing.JCheckBoxMenuItem; import javax.swing.JFrame; import javax.swing.JMenu; import javax.swing.JMenuBar; import javax.swing.JMenuItem; import javax.swing.JRadioButtonMenuItem; import javax.swing.KeyStroke; import static java.awt.event.InputEvent.*;   public class SketchFrame extends JFrame {     // 构造函数     public SketchFrame(String title){        setTitle(title);                      // 设置窗口标题        setDefaultCloseOperation( EXIT_ON_CLOSE );        setJMenuBar( menuBar );                 // 添加菜单栏到窗口               JMenu fileMenu= new JMenu( "File" );    // 创建 File 菜单        JMenu elementMenu = new JMenu( "Elements" ); // 创建 Elements 菜单        fileMenu.setMnemonic( 'F' );            // 创建快捷键        elementMenu.setMnemonic( 'E' );         // 创建快捷键               // 构造 file 下拉菜单        newItem = fileMenu.add( "new" );        // 添加 New 项目        openItem = fileMenu.add( "Open" );      // 添加 Open 项目        closeItem = fileMenu.add( "Close" );    // 添加 Close 项目        fileMenu.addSeparator();          // 添加 Separator        saveItem = fileMenu.add( "save" );      // 添加 Save 项目        saveAsItem = fileMenu.add( "Save as" ); // 添加 Save As 项目        fileMenu.addSeparator();            // 添加 Separator         printItem = fileMenu.add( "print" );    // 添加 Print 项目               // 添加 File 菜单加速键        newItem .setAccelerator(KeyStroke.getKeyStroke( 'N' , CTRL_DOWN_MASK ));        openItem .setAccelerator(KeyStroke.getKeyStroke( 'O' , CTRL_DOWN_MASK ));        saveItem .setAccelerator(KeyStroke.getKeyStroke( 'S' , CTRL_DOWN_MASK ));        printItem .setAccelerator(KeyStroke.getKeyStroke( 'P' , CTRL_DOWN_MASK ));               // 构造 Element 下拉菜单        elementMenu.add( lineItem = new JRadioButtonMenuItem( "Line" , true ));        elementMenu.add( rectangleItem = new JRadioButtonMenuItem( "Rectangle" , false ));        elementMenu.add( circleItem = new JRadioButtonMenuItem( "Circle" , false ));        elementMenu.add( curveItem = new JRadioButtonMenuItem( "Curve" , false ));        ButtonGroup types= new ButtonGroup();        types.add( lineItem );        types.add( rectangleItem );        types.add( circleItem );        types.add( curveItem );               // 添加 element 类型加速键        lineItem .setAccelerator(KeyStroke.getKeyStroke( 'L' , CTRL_DOWN_MASK ));         rectangleItem .setAccelerator(KeyStroke.getKeyStroke( 'E' , CTRL_DOWN_MASK ));         circleItem .setAccelerator(KeyStroke.getKeyStroke( 'I' , CTRL_DOWN_MASK ));        curveItem .setAccelerator(KeyStroke.getKeyStroke( 'V' , CTRL_DOWN_MASK ));               elementMenu.addSeparator();               // 创建 color 子菜单        JMenu colorMenu = new JMenu( "Color" );    //Color 子菜单        elementMenu.add(colorMenu);              // 添加子菜单        colorMenu.add( redItem = new JCheckBoxMenuItem( "Red" , false ));        colorMenu.add( yellowItem = new JCheckBoxMenuItem( "Yellow" , false ));        colorMenu.add( greenItem = new JCheckBoxMenuItem( "Green" , false ));        colorMenu.add( blueItem = new JCheckBoxMenuItem( "Blue" , true ));               // 添加 element color 加速键        redItem .setAccelerator(KeyStroke.getKeyStroke( 'R' , CTRL_DOWN_MASK ));         yellowItem .setAccelerator(KeyStroke.getKeyStroke( 'Y' , CTRL_DOWN_MASK ));        greenItem .setAccelerator(KeyStroke.getKeyStroke( 'G' , CTRL_DOWN_MASK ));        blueItem .setAccelerator(KeyStroke.getKeyStroke( 'B' , CTRL_DOWN_MASK ));               menuBar .add(fileMenu);         // 添加 file 菜单        menuBar .add(elementMenu);      // 添加 element 菜单     }         private JMenuBar menuBar = new JMenuBar();    // 窗口菜单栏         //File 菜单项目     private JMenuItem newItem , openItem , closeItem , saveItem , saveAsItem , printItem ;         //Element 菜单项目     private JRadioButtonMenuItem lineItem , rectangleItem , circleItem , curveItem , textItem ;     private JCheckBoxMenuItem redItem , yellowItem , greenItem , blueItem ; }

(2) Sketcher.java

package com.test;   import java.awt.Dimension; import java.awt.Toolkit;   import javax.swing.SwingUtilities;   import com.service.SketchFrame;   public class Sketcher {          public static void main(String[] args) {               SwingUtilities.invokeLater(                             new Runnable(){                                    public void run(){                                           creatGUI();                                    }                             }               );          }               static void creatGUI(){               window = new SketchFrame("Sketcher");               Toolkit theKit = window.getToolkit();               Dimension wndSize = theKit.getScreenSize();                             window.setBounds(wndSize.width/4, wndSize.height/4,   // 位置                                      wndSize.width/2, wndSize.height/2);  // 大小                             window.setVisible(true);                             }          private static SketchFrame window; }